Investigation of Direct and Global downward sort-wave radiation over Thessaloniki

Including the newest trends!

Athanasios Natsis

2023-01-18

Introduction

What we measure

GHI or Global

Global Horizontal Irradiance

DNI or Direct

Direct Normal Irradiance

 

What we measure

Typical spectral response

             

Have you seen those on the roof?

Pyranometer CM-21.

Global Horizontal Irradiance

Pyrheliometer CHP-1

Direct Normal Irradiance

How we processed data here

In brief…

  • Raw data
    • Inspect / Clean
    • Convert to Watt/m2
    • Quality control
  • Data grouping
    • All Sky conditions
    • Clear Sky conditions
  • Aggregation
    • Daily
    • Monthly
  • Deseasonalize

   

Results

All sky conditions Global Irradiance

 

Clear sky conditions Global Irradiance

Global

Direct

SZA dependency by Season :: ALL SKY

Winter

Spring

Summer

Autumn

Concluding

We observed

  • An increasing trend of Global Shortwave Radiation
    • Thessaloniki
    • Brightening, last ~30 years
    • On Ground level
    • Also in Direct Beam Radiation 1
  • Similar results from other sources

 

We care

  • Depends on Anthropogenic activities
    • Aerosols …
  • It is not global
    • Dimming on other time scales/regions
  • Effects
    • Radiation balance
    • Modeling
    • Solar productivity

 

We want to

  • Understand what drives the phenomenon in Thessaloniki
    • Find links with other factors/causes
  • Is there any other locally useful information
    • Weather patterns
    • Aerosol emission patterns

    Thank you !    

 

 

mail:  

The presentation will be available here: github.com/thanasisn/presentations